CANINE LEISHMANIASIS

What is canine leishmaniasis?

It is a parasitic disease due to an unicellular blood parasite, Leishmania infantum, transmitted by a tiny insect (female phlebotomidae), that rages principally on the mediterranean coast. Leishmaniasis also affects the man and a few other mammals, but the leishmania species involved can be very different.

Sources of parasites

The phlebotome absorbs leishmania when pumping the blood of a parasited dog, and it can retransmit them to another dog one or two weeks after the infecting meal. Man is an exceptional host; when he happens to be contaminated, he may develop a lesion at the inoculation point (cutaneous leishmaniasis), or an internal disease, called "Kala-Azar", inducing the enlargement of the spleen and the liver.

Spreading

In Europe, leishmaniasis is present all along the mediterranean border. In France, there are about 30 000 dogs suffering from leishmaniasis. We can distinguish 3 groups of "risky" departments, in descending order of importance:

Gard, Hérault, Bouches-du-Rhône, Var, Eastern Pyrenees and Maritim Alps. (More than 50 cases per year are diagnosed all over these departments.)

Tarn, Aveyron, and the South of Haute-Provence Alps;

Vaucluse, Aude, Ardèche and Drôme.

Symptoms in the dog

When working in an infested area, veterinarians immediatly suspect leishmaniasis as soon as a dog presents an suspicious injury on the nose, becomes apathetic and loses weight. Most often, the loss of temporal muscles gives him the air of an old dog. Some other signs are less constant: claws lengthening, dandruff in the hair, enlargement of lymphatic nodes, nose bleed, ocular inflammation, renal troubles… When they appear in a dog living an infected area, these signes must make think about leishmaniasis.

Diagnosis

In case of suspicion, the parasite can be observed through a microscope, from a sampling done in an injury, in a lymphatic node of in the bone marrow. It is also possible to look for antibodies "anti-leishmania" in the blood.

Seriousness and treatment

Leishmaniasis is a fatal disease for the dog if not treated. The treatment (as for malaria in man), can only reduce the importance of crisis, because the parasite stays alive in the different organs. No treatment is able to get rid of it, and there is no vaccine either.

Consequently the dog will stay a potential source of dissemination of the parasite during his whole life. There will always be a high number of infected phlebotomes around him. Euthanasy of affected dogs is sometimes proposed, but its interest is controversial because the dog is probably not the only one source of leishmania.

Generally, the treatment consists in series of injections of GlucantimeND, dispatched over several weeks, and renewed at each recurrent crisis. Thanks to this treatment, the life expectancy of affected dogs is considerably lengthened. Prognosis depends on the precocity of the diagnosis, on the nature of lesions that are observed, and on eventual immunitary complications.

Prevention

The best prevention consists in avoiding any contact with the vector, the phlebotome. When living in a threatened area, it is better not to let the dog ouside after dusk. Living in altitude diminishes the risk. Several insecticids can also be used: they will be applied on the dog, insisting on the nose area which is a risky spot.

Conclusion

A good knowledge of this disease and its repartition is the way to inform owners and breeders that would bring their dog in a risky area. They must imperatively get in touch with their veterinarians who will give them precisions about essential preventive measures.